1. Technical Field
The present invention relates to an electric connection box, and more particular, to an electric connection box which is compact in size, light in weight, and low in cost.
2. Related Art
A passenger car is generally mounted with electrical components such as audio system, navigation system, air conditioner, electrically-powered seat. These components are supplied with electric power from a battery and operated under the control of a controller. For connection between the electrical components, the battery and the controller, wire harnesses and an electric connection box are usually employed. The connection box comprises a case to which fuses, relays, connector terminals for wire harnesses are attached and in which a wiring board provided with bus bars for distributing large electric currents is received.
By way of example, an electric connection box shown in FIG. 7 is adapted to be retrofitted with a relay module having relays (not shown) mounted thereon. In FIG. 7, the relay module 2 is connected to the electric connection box 1 through a connection terminal 1a that is exclusive to the relay module. The electric connection box 1 and the relay module 2 have individual cases 1b and 2a, and accordingly, the electric connection box is large in size and heavy in weight as a whole. In addition, the electric connection box has much wastage in design, construction, and assembly. Hence, the connection box is high in fabrication cost. In particular, the arrangement shown in FIG. 7, which requires the connection terminal 1a for connecting the relay module 2 to the electric connection box 1, increases the number of connection points, causing large heat generation by contact resistance.